Intrinsically disordered protein domain of human ameloblastin in synthetic fusion with calmodulin increases calmodulin stability and modulates its function

Int J Biol Macromol. 2021 Jan 31:168:1-12. doi: 10.1016/j.ijbiomac.2020.11.216. Epub 2020 Dec 5.

Abstract

Constantly increasing attention to bioengineered proteins has led to the rapid development of new functional targets. Here we present the biophysical and functional characteristics of the newly designed CaM/AMBN-Ct fusion protein. The two-domain artificial target consists of calmodulin (CaM) and ameloblastin C-terminus (AMBN-Ct). CaM as a well-characterized calcium ions (Ca2+) binding protein offers plenty of options in terms of Ca2+ detection in biomedicine and biotechnologies. Highly negatively charged AMBN-Ct belongs to intrinsically disordered proteins (IDPs). CaM/AMBN-Ct was designed to open new ways of communication synergies between the domains with potential functional improvement. The character and function of CaM/AMBN-Ct were explored by biophysical and molecular modelling methods. Experimental studies have revealed increased stability and preserved CaM/AMBN-Ct function. The results of molecular dynamic simulations (MDs) outlined different interface patterns between the domains with potential allosteric communication within the fusion.

Keywords: Ameloblastin; Calmodulin; Fusion protein; Intrinsically disordered protein (IDP).

MeSH terms

  • Amino Acid Sequence / genetics
  • Binding Sites / physiology
  • Calcium / chemistry
  • Calmodulin / chemistry*
  • Dental Enamel Proteins / chemistry*
  • Dental Enamel Proteins / metabolism
  • Humans
  • Intrinsically Disordered Proteins / chemistry
  • Models, Molecular
  • Protein Binding / physiology

Substances

  • AMBN protein, human
  • Calmodulin
  • Dental Enamel Proteins
  • Intrinsically Disordered Proteins
  • Calcium